The present invention relates to a wind turbine generator power control method and system based on virtual inertia simulation. The method comprises: determining an output power of a wind turbine generator according to a real-time frequency of the power grid; and adjusting a real-time output power of the wind turbine generator to be an output power of the wind turbine generator. According to the technical scheme of the present invention, without affecting the wind power generation benefit, by setting the selection function and the parameters thereof, the wind turbine generator only responds tothe dynamic change of the system frequency, and the equivalent moment of inertia provided by the wind turbine generator for the system is increased; under the circumstance of system faults or disturbance, the wind turbine generator can block the excessive change of the frequency, raise the low point of the frequency change, and provide the reaction time for the other unit to perform primary frequency modulation; and at the same time, the problem of the secondary power drop caused by the primary frequency modulation of the wind turbine generator is avoided, and anti-disturbance of the system against the fast change of the power supply and load, and frequency stability of the high proportion wind power system are improved.